Alternate eye patching improves long-term alignment stability after surgery for intermittent exotropia: a randomised controlled trial

Abstract Background/objectives Postoperative exodrift remains a major challenge following surgical correction of intermittent exotropia (IXT), and evidence supporting adjunctive strategies to improve long-term alignment is limited. This study evaluated the effect of alternate eye patching on 12-month postoperative alignment stability after successful surgical correction in divergence excess IXT. Subjects/methods This randomised clinical trial was conducted at an institutional tertiary care centre and included 60 children (3–12 years) undergoing bilateral lateral rectus recession who were randomised only after confirmation of early postoperative alignment ( ≤ 10 prism dioptres [PD]), creating a post-success randomised design to evaluate the effect of alternate eye patching on alignment maintenance. Participants were assigned to alternate eye patching (Group A) or standard postoperative care (Group B). Patching was prescribed for 1 h daily per eye for 3 months. Patients were followed for 12 months. The primary outcome was alignment stability ( ≤ 10 PD). Secondary outcomes included exodrift ( > 10 PD), mean deviation, and reoperation rate. Results At 12 months, alignment stability was significantly higher in Group A compared with Group B (83.3% vs 60.0%, p = 0.045). Significant exodrift occurred less frequently in Group A (16.7% vs 40.0%, p = 0.045). Mean postoperative deviation was lower in Group A at all follow-up visits ( p < 0.05). No patients in Group A required reoperation compared with 10% in Group B, although this difference was not statistically significant ( p = 0.112). Conclusion Alternate eye patching may improve postoperative alignment stability and reduce postoperative exodrift for divergence excess intermittent exotropia. Early postoperative modulation of binocular visual balance may contribute to improved long-term alignment outcomes. Clinical trial registry Pan African Clinical Trial Registry ( PACTR202505751499770 ), registered on May 14, 2025. https://pactr.samrc.ac.za/